I did that upgrade last weekend, with help of my son in law. All ran right, no problem, and now my iMac is working very fast!! I put a SSD OCZ Vertex 460A 480GB under the optical drive. We take three hours to do it.
The most difficult step was step 10, just the first cable to disconnect. This cable have a very small conector and was a little hard to remove, but at the end all was fine.
This guide was extremely important to me, so I translated it to study carefully before start the upgrade. At the same way, the video was very important to show the correct way to do each step.
So, thank you very much for IFIXT team and the author, Andrew Bookholt.
Carlos Sgrillo, June 01, 2015 - from Porto Alegre, Brazil.